Cooking is often referred to as an art, not only because of the combination of ingredients that go into a particular recipe, but also due to the skill necessary for proper application and infusion of varying levels of heat over a given period of time throughout the different phases of the food preparation process. Traditional cookware appliances, such as ovens (microwave ovens being an exception), grills, heat lamps and stoves, all utilize the thermodynamic process of conduction to transfer heat from the outer surface of the food item to its interior. This is generally true regardless of the type of heat source used to heat the surface of the food, be it a radiation heat source (i.e. a heat lamp), conduction heat source (i.e. a stovetop), or a convection heat source (i.e. a convection oven or a food dehydrator).
The time and temperature necessary to cook fully and properly a specific food item through conduction is dependant upon the thermal conductivity of the item, the uncooked temperature of the item (i.e. frozen, room temperature, etc.), as well as the size and shape of the item. A food item having higher thermal conductivity will cook faster than a similarly sized and shaped food item having a lower thermal conductivity, as the heat will more quickly migrate from the outer surface to the interior. Likewise, a generally smaller or thinner food item will cook faster than a generally larger or thicker food item of the same thermal conductivity, as the heat must migrate a shorter distance through the thinner item. Frozen items require considerably more heat to cook than do non-frozen or thawed items. While increasing the cooking temperature for an item will increase the amount of heat that migrates from the surface to the interior of a food item, applying too much heat at one time will result in cooking the outer surface of the item faster than the heat can migrate to the interior, usually resulting in burning or scorching of the surface and undercooking of the interior. Therefore, obtaining real-time information regarding the temperature of the item being cooked (or at least the temperature of the pot or pan at a location as close as possible to the item being cooked), during the cooking process is often beneficial to ensure proper heating.
U.S. Pat. application Ser. No. 10/833,356, filed Apr. 28, 2004 by Imura, the disclosure of which is incorporated herein by reference in its entirety, discloses temperature controlled heatable objects, such as cookware and servingware, that each include a temperature sensor in contact with the heatable portion of the object and a Radio Frequency Identification (RFID) tag connected to the temperature sensor by a pair of wires. The RFID tag, which is located away from the heatable portion of the object (usually in a handle), acts as a transmitter (and sometimes as a receiver) to communicate with a reader/writer located in a cook-top for heating the object, providing temperature information and other information regarding the object (such as heating characteristics) to the cook-top. The temperature information and the heating information are used by the cook-top to control the temperature of the object. The heatable objects disclosed in by Imura are particularly well suited for use with the induction heating systems and methods described in U.S. Pat. No. 6,320,169 to Clothier, and in U.S. Pat. application Ser. No. 10/355,989 to Clothier, the disclosures of which are incorporated herein by reference in their entirety, and overcome a number of problems inherent in heatable objects of the prior art. Notwithstanding, heatable objects such as those described in Imura, and in particular cookware objects, are subjected to extremely harsh operating conditions in which robust design is necessary to ensure proper functionality. Components of the heatable objects of Imura, such as the RFID tag, temperature sensor, and wires connecting the RFID tag to the temperature sensor are fairly delicate and susceptible to malfunction.
Imura addresses the delicate nature of these components by placing the RFID tag away from the heatable portion of the object (i.e. in the handle of a pot or pan). Imura houses the RFID tag in a special handle for the heatable object that supports the RFID tag and which is designed to provide a moisture barrier and allow moisture to drain away from the RFID tag. Imura provides shielding for the wires by locating the wires in a channel of a metal receiver that connects a handle to the heatable object. In addition, Imura provides shielding for the temperature sensor by at least partially imbedding the senor in the heatable portion of the object and surrounding the sensor with a potting material, and in some cases by covering any exposed portion of the sensor with a portion of the receiver. Notwithstanding Imura's substantial efforts to protect these sensitive components, these components are still susceptible to diminished functionality caused by the harsh operating environment in which the heatable objects are used. In particular, despite Imura's design considerations, the components are still highly susceptible to diminished functionality due to exposure to moisture. For example, prior art conductor wires are manufactured of a fiberglass (typically a fiberglass insulated nickel metal copper wire) material, which tends to absorb moisture and cause distorted information. Therefore it would be beneficial to further protect these sensitive components from moisture.